Bark removing lathe



cm 19 1950 G. HAUMANN 295349671 BARK REMOVING LATHE Filed Dec. 8. 194? 4Sheetsdhee INVENTOR. GEORGE HAUMANN ATTORNEY D860 1950 G. HAUMANN2,534,671

' BARK REMOVING LATHE Filed Dec. 8. 194'? 4 Sheets-Sheet 2 INVENTOR.GEORGE HAUMANNv ATTORNEY Dec. 19, 1950 e. HAUMANN BARK REMOVING LATHEFiled has. 8. 194"? 4 Sheets-Sheet 3 I I i Inmnmnnnnnnnnm INVEN TOR.GEORGE HAUMAN N ATTOR N EY Dec 19, R950 6. HAUMANN 2,534,671

BARK REMOVING LATHE Filed Dec. 8. 194'? 4 Sheets-Sheet 4 INVENTOR.GEORGE HAUMAN N ATTORNEY Patented Dec. 19, 1950 UHED STATES PATENTOFFICE 11 Claims.

This invention relates to a bark removing lathe, the same being amachine for preliminary barking and surfacing of a log, preparatory toplacing it in a veneer lathe in the manufacture of veneer.

The object is to replace the conventional barkers that usually waste aconsiderable amount of the valuable white or sap wood, which in plywoodmanufacture is equally as valuable as the heartwood.

Another object of the invention is to condition the surface of a log,which means to reduce surface irregularities a shaving at a time as aknife can handle it, without wasting good material; meaning to provide amachine, which when barking preparatory to placing the log in a veneerlathe will, if a relatively high hump, knot or pro ection isencountered, automatically move the conditioning knife back and limitthe bite or amount of cut it takes, to prevent stalling the machine ordamaging the knife or its mounting, which otherwise might be expected,as some of the knots thus encountered are extremely hard.

Still another object is to provide manual controls whereby the knife canbe made to align to the taper and irregular contour of the log.

The foregoing and other objects that will be apparent, are found in thespecification and pointed out in the claims.

Drawings accompany and form a part hereof, showing an operativestructure for carrying out the purposes of the invention. l"he drawingsare as follows:

Fig. l is a plan view of the entire machine;

Fig. 2 is an elevation of the machine of Fig. 1;

Fig. 3 is a partially broken away side elevation on the plane 33, Fig.1;

Fig. 4 is a sectional elevation taken from the plane -l-Al, Fig. 5;

Fig. 5 is a fragmentary view in plan illustrating the piston control tobe latLr described;

Fig. 6 is much the same as Fig. 5, it illustrates a bumper that is animportant feature of the machine; and

Fig. 'I is a front elevation taken on the cutter blade, the carriagetherefor and the means of mounting the same on the frame of the machine,partially in section taken on the plane li, Fig. 4%.

Describing the drawings in greater detail.

Numeral i represents a base that supports a frame 2. Revolubly mountedon the frame 2, is a headstock 3, and oppositely mounted is a tailstock4, both of which need no description in detail. The headstock 3, isrevolved by the motor 5, to which it is connected within the gear case6, and both headstock and tailstock are movable by respective motors Iand 8, to open up the distance between themselves to take in a log to beconditioned; indicated as present by numeral 9, Figs. 3 and 4, andclosable to revolve the log in the well known manner. The lead blocks 29and 2i are formed with cooperative integral guides 13 that work withrelatively stationary parts 22 to preserve straight line operation.

The whole assembly so far described may be accurately regarded as thelathe portion of the log conditioner, the setting for the invention, andI will now proceed to describe the relatively stationary tool setup thatconditions the log when it is revolved in the lathe and the tool is heldagainst it to remove surface irregularities, and contains the novelstructures that by their operation satisfy the objects of the invention.

Ihe instrument that rcmo'ves the irregularities referred to, is theknife blade Hi, the bevel angle of which, ii, is shown to be -tangent tothe horizontal centernne of the log 9 in Fig. 4. The blade it is securedto the blade carrier i2, and the blade carrier 12, in turn, is rigidlymounted within the cutterhead l3. Numeral i3 has been chosen todesignate the cutterhead as a whole, and includes the knife blade ill,the blade carrier i2 and other parts not specifically mentioned.

cutterhead I3, is carried forward into engagement with a log of anydiameter within the capacity of the machine by the lead screws Hi andit, operated by the worm gear sets It and it, said screws operablethrough the belt it, by the reversible motor i9; and, as the load screwsrevolve they may reciprocably move the lead blocks 2.; and 2!, whichslide in contact with the guides 22 and 23 made on rigid parts of theframe 2, as shown in Fig. l.

I'he following is a description of the cutterhead it and its mounting,which also incorporates a description of its mode of operation.

Leadscrews Hi and I5 are operatively mounted on the frame .2 to berevolved by worm wheels Hi and It operable by the reversible motor 19.The screws are threadably engaged with lead blocks 2;; and 21 to advanceand withdraw the cutterhead 3 with respect to the perimeter of a log.

The cutterhead i3 is indirectly connected to lead blocks 23 and 24through the yokes 28 and 29; the yokes having straight portions whichare rigid with the lead blocks and angularly bent portions overhangingthe ends of the cutterhead pivotally connected to air cylinders 26 and2'! at opposite ends by pivots 3i and 3|. The air cylinders containpistons (not shown) and have piston rods such as 32 in cylinder 26; bothpiston rods being pivotally connected to the cutterhead 13 by pivot pinssuch as 35 at the right of center, Fig. l. The cylinders 26 and 27 arecontrollably energize through throttles such as 38 and 39 through theconduits and 4|.

The cutterhead I3 is supported at both ends by arcuate projecting ribs25, swingable in straight slots 2 formed in the lead blocks 2| (or 29)and the lead blocks are concurrently movable by leadscrews l4 and !5,which in turn are operable by the reversible motor l} operating throughthe belt 38 to drive the worm gear sets it and ll connected to theleadscrews I4 and 55 as shown in Fig. l.

The mode of operation will now be plain. The cutterhead is fed forwardinto contact with a log to be conditioned by bringing the edge of theknife H into tangential contact by operation of the leadscrews if; and55 after the well understood fe-zd of a lathe. The leadscrews move thewhole cutterhead assembly, as shown in Fig. 1, but unlike a lathe, theair cylinders and 21', when charged with air under pressure, provide a'esilient cushion, the yielding of which can modify shocks occasioned byhitting very hard knots.

The cutterhead is floatingly held with respect to the horizontal planebut prevented from varying in the vertical aspect by the ribs and slotspreviously mentioned. By skillful ariation of the air pressure in thecylinders 23 and 2?, the operator will be able to make knife contactwith a log surface that takes the natural taper of the log intoconsideration, if this is expedient, and at the same time his operationof the air cylinders will not detract from the effectiveness of thebumper 52 when it is contacted by a protuberance or knot, such as 5!(Fig. i) to prevent overloading the knife. The knot will strike thebumper and force the cutterhead back so that the knife takes a moderatecut and removes the knot by a succession of cuts without wastingvaluable timber.

By virtue of the pivots 3! and 35, with a corresponding one on pistonrod 32 and the conduits 4e and ii, the movement of the cutterhead i3, ina horizontal plane only, is well provided for.

Several modes of operation of the cutterhead will be at once apparent.ihe preferred one is now described. Due to the positioning of thecutting knife, the resistance of the substance of the log tends to driveit back out of cutting action. Assume that a log, Fig. 3, is making itsinitial revolution in the conditioning operation, a shaving S is beingcut, indicated by the arrow 59; that it carries on its perimeter a knot5!, whic is assumed to be beyond the capacity of the blade ii, to removeby passing through the base of the knot; but, the cutterhead is formedwith a bumper 52, which is an integral part of or made rigid with thecutterhead l3, and contact of the knot 5i with the bumper 52 will causethe cutterhead !3 to be forced back until the depth of out, indicated at53, Fig. 4, will be maintained. It will be presumed that the amount ofair pressure carri d and available to operate the cylinders and 2's,will be less than that which would overload the cutterhead i3 even ifthe knot were near the center of the log and it was necessary to forceback both pistons to reduce the depth of cut to what the machine wouldsafely stand.

Obviously also, the operator stationed at the controls 38 and 39, cannot only swing the cutterhead [3 to accommodate the same to the taper ofthe log, but can also, to a considerable extent, control the load on thecutterhead and so manipulate the machine that the least amount ofexternal log surface is removed that is required to condition the log.

The cutterhead is shown in what is believed to be its optimum positionwith respect to the log to be conditioned; that is, at the horizontalcenterline of the log, so that the reaction or r thrust of the logagainst the cutter blade is as near straight as possible. Obviously, theaction can be realized to some extent as the cutterhead is raisedtowards the top of the log. In the claims, the optimum position wherenamed will not be intended to exclude any other position where abeneficial result of the semi-floating cutterhead can be realized.

For logs of a given class, the maximum depth of cut may be relativelyfixed and is of course the distance between the point of the blade l8and the lower side of the roller 55; but that depth is instantlylessened if a protuberance pushes the cutterhead l3 away by contactingthe bumper 52 as explained, and several revolutions of the log may benecessary to dispose of the protuberance. This is under control of theoperator by the valve 38 and 39, and operation of the lead screws Hi andi5. When reducing a knot by successive cuts, he backs off the leadscrews so that the log body is not reduced while successive cuts areremoved from the knot.

Having fully explained the advantages of my semi-floating cutterhead fora lathe type log conditioner, the manner of its construction and itsmode of operation, what I claim as new and desire to secure by LettersPatent, is:

l. A log conditioner of the lathe type wherein a log is held'betweenhead and tail stocks and revolved against a cutting implement comprisinga frame, revolving head and tailstocks operably mounted thereon, acutterhead movable towards and away from a log held between said headand tailstocks, leadscrews operably 'mounted on said frame, lead blocksthreadably engaged by said leadscrews, means for revolving saidleadscrews, yokes made rigid with said lead blocks and overhanging therear sides of said cutterhead at the ends thereof, air cylinders withpiston rods therein pivotally connected between said overhang of theyokes and said cutterhead,'iiuid ressure conduits connectedindependently to said air cylinders and independent manual controlthrottles for said conduits.

2. A log conditioning machine of the lathe type wherein a log isrevolved against a cutter implement, having in combination there' "th asemifloating cutter head, lead screw operated means for bringing saidcutter head into operative contact with a log, characterized by aplurality of air cylinders positioned between said lead screw operatedmeans and said cutterhead whereby the attack of the cutterhead againstthe log is determined by the amount of pressure that the air cylindersdeliver to the cutterhead in excess of the reaction force that therevolving log delivers against the cutterhead.

3. A cutterhead for a lathe type of log conditioner wherein a log is tobe conditioned by re volving against a relatively stationary blade,comprising a cutter head, a cutting blade carried thereby, asemi-floating mounting for said cutterhead that permits unequal advanceor retraction of the cutterhead within desirable limits, lead screwmeans for advancing the cutterhead to condition a log by removing partsof its surface and air cylinder means positioned between said leadscrewmeans and said cutterhead, operably connected thereto with control meanstherefor, to effectively cushion the attack of the cutting blade againstthe log proportionately to the air pressure that is within said aircylinders.

4. The combination as claimed in claim 3 and including a bumper maderigid with the said cutterhead and positioned in advance of the blade tocontact a protuberance before it reaches the blade, said bumpereffective upon contact with such protuberance on the log to drive thecutterhead back to reduce the amount of a forthcoming cut on saidprotuberance.

5. A log conditioning machine comprising a base, a frame mounted on saidbase, revoluble headstock and tailstock means revolubly mounted on saidframe, a pair of leadscrews mounted on and supported on the frame normalto the axis of the head and tail stocks, an elongated semifloatingcutterhead indirectly responsively operable by said leadscrews to attackor withdraw from the log, air cylinders directly connected to saidcutterhead in cushioning relationship be tween said leadscrews andcutterhead and independent manually operable control means for said aircylinders.

6. A machine for conditioning 10g surfaces prior to cutting them intoveneer for veneer manufacture, comprising a base, a frame mountsthereon, opposed coaxial head and tail stocks revolubly mounted on saidframe, an elongated semi-floating cutterhead spaced from andsubstantially in parallelism with said frame, leadscrews and leadscrewoperated means mounted on said frame in normal relationship to the axisof the head and tail stocks, to attack a log revolved thereby, and anair cylinder interpositioned between each end of the cutterhead and itsoperating leadscrew to cushion the same and effective upon selectivecontrol thereof to vary the alignment of the cutterhead with respect tothe axis of a revolving log.

7. The combination as claimed in claim 6 and including a bumper plate onsaid cutterhead positioned in advance of the cutter part of thecutterhead which, upon being contacted by a protuberance on arevolvinglog, tends to throw the cutterhead out of cutting engagement with thelog save for a cut of fixed amount on the protuberance.

8. A lathe type barker and. conditioner for logs having in combinationtherewith an elongated emi-floating cutterhead comprising a carriageportion, a cutter portion mounted on said carriage portion, a pair ofspaced apart air cylinders comprising yielding means between saidcarriage and cutter portions, and a bumper made rigid with said cutterportion, positioned to precede the cutting part of said cutter portionto be contacted by a knot or the like, if any, thus to force the cutterportion backwards against said air cylinders to limit the cut of saidcutter portion into such a hazardous knot, or the like.

9. A log conditioning machine comprising a base, a frame mounted on saidbase, a revoluble headstock, tailstock means revolubly mounted on saidframe, a pair of leadscrews mounted on and supported on the frame normalto the axis of the head and tail stocks, an elongated semifioatingcutterhead responsively operable by said leadscrews to attack orwithdraw from the log with air cylinder backing means directly connectedto said cutterhead in cushioning relationship between said lead screwsand cutterhead and independent manually operable control means for saidair cylinder backing means.

10. A log conditioning machine comprising a log lathe, a cutterheadtherefor, means for advancing and Withdrawing said cutterhead, a bladeholder fioatingly mounted on said cutterhead, a blade mounted thereon,air cylinders at each end of said blade holder positioned between saidblade holder and said advancing means to resiliently hold said blade incontact with a log in said lathe and a bumper mounted on said bladeholder positioned to contact a protuberance on a log before it contactssaid blade, to overcome said air cylinders and limit the depth of cut ofsaid blade into such protuberance.

11. The combination as claimed in claim 10, wherein the air cylindershave separate air supply control means for independent regulation.

GEORGE HAUMANN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 398,593 Ellis Feb. 26, 1889675,936 Dawson June 11, 1901 1,471,450 Collier Oct. 23, 1923 1,877,013Moore Sept. 13, 1932 2,340,513 Deuring Feb. 1, 1944 2,340,532 JacksonFeb. 1, 1944 2,411,623 Jaques Nov. 26, 1946

